[media] media: Pipelines and media streams
authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Wed, 25 Aug 2010 12:00:41 +0000 (09:00 -0300)
committerMauro Carvalho Chehab <mchehab@redhat.com>
Tue, 22 Mar 2011 07:53:17 +0000 (04:53 -0300)
commite02188c90f6ef61f0844c42508fe603c5d4fa42b
tree7b0ff940b37ba6bf53c7cea7fadbb697ec2d156a
parent97548ed4c4661502cdfd1aabd5d3876fa4f5cc2e
[media] media: Pipelines and media streams

Drivers often need to associate pipeline objects to entities, and to
take stream state into account when configuring entities and links. The
pipeline API helps drivers manage that information.

When starting streaming, drivers call media_entity_pipeline_start(). The
function marks all entities connected to the given entity through
enabled links, either directly or indirectly, as streaming. Similarly,
when stopping the stream, drivers call media_entity_pipeline_stop().

The media_entity_pipeline_start() function takes a pointer to a media
pipeline and stores it in every entity in the graph. Drivers should
embed the media_pipeline structure in higher-level pipeline structures
and can then access the pipeline through the media_entity structure.

Link configuration will fail with -EBUSY by default if either end of the
link is a streaming entity, unless the link is marked with the
MEDIA_LNK_FL_DYNAMIC flag.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Documentation/DocBook/v4l/media-ioc-enum-links.xml
Documentation/DocBook/v4l/media-ioc-setup-link.xml
Documentation/media-framework.txt
drivers/media/media-entity.c
include/linux/media.h
include/media/media-entity.h